ACR Journal

CMYK / .ai CMYK / .ai CMYK / .ai acrjournal.uk 27 REFRIGERATION For this site, noise levels were a key consideration, with residential housing less than 10 metres from the plant area. The plant selection criteria stated a noise level of no more than 30 dB(A) at 10m, which is very challenging using conventional semi-hermetic booster technology. However, the new transcritical scroll technology and the Arctic Circle system design achieved this with ease. Commissioning and installation were carried out by CG Refrigeration and overseen by the Arctic Circle technical services team and Emerson technical representatives. During commissioning, the team adjusted the compressor envelopes, adjusted the cabinets’ superheat settings, and monitored oil return behaviour to ensure the correct system set up. After the successful commissioning, the site passed its six-week proving period with no alarms and no works orders raised. The system was then handed over to Arctic Circle’s maintenance providers, CG Refrigeration and Ryan Jayberg. The site was continuously monitored and reviewed during its life to optimise system performance and provide feedback to further the compressor development. In addition, the systems development compressors were periodically replaced and sent back for inspection for wear and to further develop the future system efficiency. The compressors were finally replaced with full production models in June 2021. As a result, as part of an 18-month field test, the systems were constantly monitored, adjusted, and provided feedback on system performance. This enabled Emerson to fast track the development of the transcritical scroll technology and be brought to mass production much sooner than previous compressor developments. Revolutionary step forward This product has the potential to revolutionise the market in small to medium-sized retail applications. The benefits of having lower noise levels, smaller footprints and less weight than semi-hermetic compressors make it the perfect choice for convenience stores in urban areas where space requirements are limited and noise restrictions are very tight. The possibilities for enhancing system performance through using Emerson’s Copeland CO 2 scroll technology are vast. Offering a significant life- cycle cost improvement and a physical footprint and noise level reduction versus conventional technology. There are endless possibilities around maximising the potential of this technology across a whole host of applications. Adrian Crowther, engineering design and standards manager – refrigeration, Co-op, commented: “With a lower noise level than reciprocating compressors, this brand-new CO 2  scroll technology ensures that the most stringent noise levels can be achieved. With so many urban store locations, this is especially important for the Co-op. The noise level of the running system was so low that I asked, ‘is the unit actually running?’ when first entering the plant enclosure. The Co-op is extremely proud to have been able to facilitate this enterprising technology, which is probably the most well-kept secret in recent times when it comes to new refrigeration solutions design. The plant has performed admirably during the past 18 months and to now have the factory manufactured versions is a significant step forward from the initial prototype development. The compressors are very compact and offer a smaller footprint plant design as available space is at a real premium for The Co-op”. Mike Gittoes, managing director, Arctic Circle, said: “When Emerson approached us as a partner to trial this new technology, we were excited about the opportunities this would present for system design innovation. This technology will become a real step-change for innovation in the industry and will also lend itself well in the future to integrated heat recovery or standalone heat pump applications. This is due to the enhanced vapour injection technology enabling increased system efficiency at elevated gas cooler pressures allowing the system to raise head pressure to generate heat effectively while minimising the penalties for transcritical operation. Traditional scroll compressor technology has been an industry benchmark for years for small retail applications. The evolution of scroll technology to transcritical CO 2 will deliver great benefits like increased efficiency, lower noise levels and enable smaller systems. As soon as this technology is available for full commercial release Arctic Circle and Emerson are confident that it will be adopted and rolled out across the small to medium convenience retail estate.”  Laboratory testing pack system